Whether you are building homes using foundations made of concrete block, poured concrete, concrete poured into foam insulation forms, precast concrete walls, or some other system, greening these systems means paying attention to several matters that reduce any negative impact that the foundations could have on the environment and the people living in the home. If the site is large enough,we want to keep most of the topsoil on the site. The topsoil, unless it is laced with lead or other contaminants, or is from a brownfield, is the natural soil for this site. Removing it and then replacing it not only adds an unnecessary transportation (and therefore, environmental) cost, but also spoils the natural conditions that could support plant life common to the area. We also want to use the smallest foundation necessary, so that displacement of large amounts of soil is not required. If a slab-on-grade home is to be considered, green building methods would recommend the use of a frost-protected shallow foundation, which can usually be constructed without excavating more than 1 ft below grade. Builders using this system have significantly reduced their building costs. &...